Express-public-files-overlays NPM

Express Public Files Overlays

Serves static files from one or more paths in your URL structure. Each URL path can map to one or more directories which will be searched in turn for a file to serve.

Configuration

The components in this package make use of the app.locals.publicFiles namespace. The preparePublicFiles() function helps set up the data structure correctly.

Configuration environment variables for the example.

PUBLIC_FILES - JSON-encoded mapping of URL paths to serve static files at, and the directories to look in for each file under that path. e.g. {"/public/js": ["./jquery/", "./react"], "/theme": ["./static"]}

Any configuration from PUBLIC_FILES gets merged into existing configuration such that it is used in preference to it. Effectively, the PUBLIC_FILES settings override settings defined in code.

Additionally:

DEBUG - Include express-public-files-overlays to get debug output from the express-public-files-overlays library itself and express-public-files-overlays:server for messages from the example server.

Internal Workings

Internally, the code is designed to work in these stages:

publicFilesFromEnv(app) - Parses and returns the config from the PUBLIC_FILES environment variable
preparePublicFiles(app, userDirs) - Sets up the publicFiles data structure in app.locals and makes app.locals.publicFiles.overlay() available (see next). userDirs is optional. You usually pass the output of publicFilesFromEnv(app) as the userDirs variable and then use overlay() (see next) to add any public files directoires your library needs to the internal libDirs.
app.locals.publicFiles.overlay(urlPath, dirs) - A function other libraries can use to merge any overlays they need into the libDirs configuration. The userDirs configuration will always overlay over the libDirs configuration, even if it is set up earlier.
setupPublicFiles(app) - Installs the middleware based on the settings in app.locals.publicFiles. This should always come last.